Area 51 became famous because of the rumors created to discredit its use to house alien crafts.
Area 51 is just one place that has become famous.
There are many unknown places.
I don't believe they are holding anything alien at Area 51 anymore.
Area 51 is just another military holding place.
It was used for certain secret things before, but not any more because too many people are too interested in it.
Area 51 is a red herring.
Area 51 keeps interested civilians preoccupied.
It's so secured to keep it interesting.
There may be secrets held there, but all government is secret.